Some Clinton backers said they were intentionally withholding their contributions to the party, arguing that Howard Dean, the D.N.C.’s chairman, has left the situation in the hands of the states and the candidates, as opposed to exercising leadership to resolve it.

“My wife and I could max out, and we won’t,” said Ira Leesfield, a Miami lawyer who has given $61,500 to the committee since 1997. “We’re dissatisfied with the D.N.C. not taking the bull by the horns.

Wealthy donors say: “Why won’t you exhibit leadership and do what I say?”